My father-in-law passed along a beautiful 82 300sd with 167,000 miles. He is the original owner and maintained it scrupulously (I've got all the records). He says it has lost a bit of power over the years, but it gets going okay when it is warm. It trucked up some long freeway grades (from California to Seattle) at 70mph, no problem -- could have gone 80-85 at least. It got 26 mpg on the long trip at a consistent 70mph on the cruise.

It burns a lot of oil -- up to a quart a tank of 20-50 if cruising at higher rpms. But it still goes pretty good and starts without complaint. Apparently it leaks just a little bit of oil at some blow-by or recirculation pipe (on the block beneath the turbo), but I'm thinking it is the ring or valves or something like that. Is there anything I can do about the oil consumption? Should I be worried?

What are the most important things I can do to maintain an older diesel? What is important to know?

Please help me keep this truly wonderful car running for a few more years

Thats a lot of oil consumption and seems excessive for such a relatively low mile engine. The fuel mileage you are getting seems right, I doubt you have any engine problems. Is it the turbo oil drain line going to the turbo that's leaking? There is a seal kit for the drain line. I would start here. As far as maintenance, the most important things to do is change the oil hot and often and keep the fuel filters clean. Welcome to the diesel club and good luck.

Welcome to the world of diesels, Of course no one would want to get a car under these types of circumstances. I am also new to diesel ownership, 3 months and counting. Though my father has had his MB 300D for 5 years. I also own a "SD", except mine is a W116 (1980). You have a W126 chassis, which I have read is the best chassis MB ever made. The best thing you can do for your engine is change the oil often and stick with OEM filters. These filters, MANN and Hengst, can be bought from our hosts here. Just go to the "partsshop". There are others on this board that can give you any model specific info. This is definetly the place to learn about MB diesels, or for that matter, anything MB. Agai welcome to the world of Mercedes and diesels, and happy New Year.

I too have inherited a 1984 300D turbo - fortunately my uncle still lives, he has lost his vision. I have had the car for 2 years, it runs great, burns little oil and gets 20-28 miles per (now expensive) gallon depending where I am. It is now developing pesky problems of aging and I would like to attempt the repairs, since the local shop is costing me much too much. Here are the pesky problems:
1. heater turns out heat only when on "max." when I adjust thermostat to lower temperatures only cold (air conditioned?) air comes out.
2. sun roof motor runs all the time. I have disconnected power since I have determined rocker switch is not rocking well.
3. wont start in this weather (cold). Block heater helps the problem. Glow plug light on dash goes on intermittently, sometimes if I tap the glow plug relay. Right now this is my major problem.

The car is great, just drove to Parris Island and back this weekend. I want to become a little more self sufficient.

So how do I start? Where do I get shop manuals? Clues to diagnoses? I can have access to a shop at the nearby Army base...but know little about cars.

...to the MB Diesel world!
As mentioned above, regular oil changes are a must. Do a search on the subject of oil, and you will find a plethora of information as to viscosities, and types. One thing that may have been overlooked, is the fact that neither the D nor the SD have hydraulic lifters...the valves must be adjusted every 15K miles according to MaBenz. (this may be of some aid in cold start, and performance issues in your cases)
An additive I'd like to recommend is RedLine Diesel Fuel catalyst...its a good thing all the way around (read the bottle and you'll know what I mean...there is also a link to their site from here, explaining its use)
Dr. G, how many miles on yours?

I think you will find that almost everyone here agrees that the 617.95x (5cyl diesels) are quite the workhorses and will give hundreds of thousands of miles of service.

(the 4 cylinders are also, but neither one of you has one. )

Those were my welcome, and my 2¢
-Larry

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein

Thanks very much for the info so far. Very helpful. I think I found the reason for the burning oil on another thread:

"M.B. Doc you mentioned problems with some 82-83 model engines? The rings you mentioned not seating right, these are the oil control rings, not the compression rings right?"

This seems to be the problem, especially since my 300sd has always burned a good amount of oil -- the rate of oil burn has barely changed over the past 18 years. Glad I'm not going to need a new engine any time soon!

Thanks for the gracious welcome to the forum. As I have said before, I want to begin working on the car myself but I know little about cars. I know I can come to this forum for collegial help for particular problems, but what do I need in the way of shop manuals and descriptive materials to begin to educate myself about the basics? For instance, where do I learn the very basics - like fluids changes? How do I learn enough to actually carry out the glow plug tests and replacements, etc... I feel good evaluating and diagnosing (I was a doctor in my past life), I just need some kind of guide to the symptoms and the surgery. I do have access to a military auto shop, so I assume tools and bay space is not a problem. Can I learn to be a shadetree diesel 300D turbo mechanic. Or am I being too ambitious?

I think that you will find that for most, if not all DIY items on your Benz, there is a post for it somewhere in the archives. Do a search first, and then if you are not sure, or just to confirm, post here, and a bunch of us will be happy to help!
-Larry

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein

The simplest way to start to learn about your car, is to go to any auto parts store and get a chilton's or Hayne's manual for your model(call first to see if they have it). You will find all the information about basic fluid changes in that book. It's a cheap way to get your feet wet.

Chilton's makes a manual for all models from 1974-84, part no. 6809. Hayne's does not have a manual for W116 either, they must be very picky. The Chilton's manual is great for someone who is just starting out in automotive repair.

Just this past weekend I saw that Chilton's manual at a Borders bookstore. I quickly thought about buying it but after flipping through the pages I decided not to. The book is the old style (small). The book covers 10 years of cars. This would be 4,5,6, and 8 cyl. engines, gas and diesels. Also it covered 4 or 5 different chassis'. The book was only about 3/4 inch thick. A book this thin, covering this many engines and chassis', tends to be very general. Granted the book did have specs charts for all the engines and such, but I would want something a little more specific. I recently ordered the MB CD manual for my particular chassis, so I won't be needing to find a paper manual. Personally, I like Haynes manuals over Chiltons. At least in the past, Chilton's seems to be geared to people who know whats wrong and just need to replace the part. Haynes tells you how the systems are supposed to work and has a large troubleshooting Q/A section in the front of their books. Also, Haynes has real photos, where as Chiltons has "artist renderings". I do wish Haynes would print a manual for my W116, but like Patsy said, I guess they're being picky.